Neurite Outgrowth in Fibrin Gels Is Regulated by Substrate Stiffness
Neurite Outgrowth in Fibrin Gels Is Regulated by Substrate Stiffness
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DOI：
10.1089/ten.tea.2011.0030
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发表时间：
2011-12-01
影响因子：
4.1
通讯作者：
Bannerman, Peter
中科院分区：
文献类型：
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作者：
Man, Alan J.;Davis, Hillary E.;Bannerman, Peter
纤维蛋白是一种有前途的基质，可用于促进神经修复，因为它在周围神经损伤中自然存在，并且可以调节该基质的生物物理特性以调节组织再生。在这项研究中，我们研究了纤维蛋白凝胶的物理和机械特性对背根神经节（DRG）神经突延伸的影响。纤维蛋白原浓度的增加增加了纤维蛋白链的数量，导致孔径减小和硬度增加。当 DRG 外植体在纤维蛋白原浓度增加（从 9.5 至 141 mg/mL）的纤维蛋白凝胶中培养时，神经突延伸减少。氯化钠的添加还增加了纤维蛋白丝的数量，减少了纤维直径和孔隙率，同时增加了机械强度，并且神经突延伸的减少与氯化钠含量的增加相关。我们确定，纤维蛋白凝胶内的神经突延伸依赖于纤维蛋白溶解，并且是由截留的 DRG 分泌的丝氨酸蛋白酶和基质金属蛋白酶介导的，这一点通过在针对这些酶的抑制剂和实时聚合酶链式反应存在的情况下培养细胞来证实。总而言之，这项研究的结果为纤维蛋白凝胶生物物理特性对神经突延伸的影响提供了新的见解，并提出了提高这些材料用作神经引导导管时的功效的新机会。
Fibrin is a promising matrix for use in promoting nerve repair given its natural occurrence in peripheral nerve injuries, and the biophysical properties of this matrix can be regulated to modulate tissue regeneration. In this study, we examined the effect of physical and mechanical properties of fibrin gels on dorsal root ganglia (DRG) neurite extension. Increases in fibrinogen concentration increased the number of fibrin strands, resulting in decreased pore size and increased stiffness. Neurite extension was reduced when DRG explants were cultured within fibrin gels of increasing fibrinogen concentrations (from 9.5 to 141 mg/mL). The addition of NaCl also increased the number of fibrin strands, reducing fiber diameter and porosity, while increasing mechanical strength, and reductions in neurite extension correlated with increases in NaCl content. We determined that neurite extension within fibrin gels is dependent on fibrinolysis and is mediated by the secretion of serine proteases and matrix metalloproteinases by entrapped DRGs, as confirmed by culturing cells in the presence of inhibitors against these enzymes and real-time-polymerase chain reaction. Taken together, the results of this study provide new insight into the effect of fibrin gel biophysical properties on neurite extension and suggest new opportunities to improve the efficacy of these materials when used as nerve guidance conduits.